Catani, Stefano; de Florian, Daniel; Rodrigo García, Germán Vicente | |
This document is a artículoDate2004 | |
Este documento está disponible también en : http://hdl.handle.net/10550/44449 |
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We consider the singular behaviour of one-loop QCD matrix elements when several external partons become simultaneously parallel. We present a new factorization formula that describes the singular collinear behaviour directly in colour space. The collinear singularities are embodied in process-independent splitting matrices that depend on the momenta, flavours, spins and colours of the collinear partons. We give the general structure of the infrared and ultraviolet divergences of the one-loop splitting matrices. We also present explicit one-loop results for the triple collinear splitting, q→qQ¯Q, of a quark and a quark--antiquark pair of different flavours. The one-loop triple collinear splitting is one of the ingredients that can be used to compute the evolution of parton distributions at the next-to-next-to-leading order in QCD perturbation theory. | |
Catani, Stefano de Florian, Daniel Rodrigo García, Germán Vicente 2004 The triple collinear limit of one-loop QCD amplitudes Physics Letters B 586 3-4 323 331 |
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http://dx.doi.org/10.1016/j.physletb.2004.02.039 |